Many surgical procedures are typically performed while the patient is under general anesthesia. During these procedures, the patient is given a combination of medications to cause a loss of consciousness and muscle paralysis. The medications that cause loss of consciousness and muscle paralysis also interfere with the patient's ability to breath. Accordingly, patients often undergo tracheal intubation during these procedures so that the patient may be connected to an external ventilator or breathing circuit. Patients may also be intubated for nonsurgical conditions in which enhanced oxygen delivery is required. Tracheal intubation may also be used in other circumstances.
During tracheal intubation, an endotracheal tube is placed in the patient's airway. Generally, the endotracheal tube is advanced through the patient's nose or mouth into the patient's trachea. The endotracheal tube is then connected to an external ventilator or breathing circuit. The ventilator is then able to breath for the patient, delivering oxygen into the patient's lungs.
The patient's vocal cords and the space between them form the entrance to the trachea, these structures are also known as the glottis. The glottis is visible from and may be accessed through the pharynx. The pharynx is the portion of the upper airway that is located behind the patient's mouth and below the patient's nasal cavity. The mouth and the nasal cavity meet in the pharynx. Additionally, the esophagus and the glottis may be accessed through the pharynx. During the intubation process, the endotracheal tube must be carefully advanced through the patient's pharynx and placed through the vocal cords into the trachea.
The intubation process interferes with the patient's ability to breathe and thus deliver oxygen to the body independently. If the patient is without oxygen for more than two or three minutes, tissue injury may occur, which can lead to death or permanent brain damage. Accordingly, the intubation process must be performed quickly and accurately.